Electromagnetic SpectrumLight as a Wave

Learning Objectives• Understand the electromagnetic spectrum• Understand the relationships between and

perform calculations involving wavelength, frequency, and the speed of light

Electromagnetic Spectrum

• Electromagnetic radiation – a form of energy that displays characteristics of a wave as it moves through space

Light as a Wave

• Waves are characterized by wavelengths and frequencies– Wavelength ( λ ) – the distance

between the same points on two successive waves

• Units of meters (m)

– Frequency ( f ) – the number of wave cycles that are completed during a unit of time• Units of hertz, Hz, or inverse seconds,

s-1 or 1/s

Light as a Wave

• Speed of light ( c ) – the speed at which electromagnetic radiation travels– Speed of light is a constant

• Units of speed of light are meters per second

Light as a Wave

Finding Frequency, Given Wavelength

Ex) What is the frequency of electromagnetic radiation whose wavelength is 5.50 × 10–7 m?

IV. Conversions needed? V. Intermediates needed?VI. Solve

VII. Does the result make sense?

I. StrategyII. Given and unknown

III. Formula

No.

No.

Yes.

Finding Wavelength, Given Frequency

Ex) What is the wavelength of electromagnetic radiation whose frequency is 6.50 × 1014 Hz?

IV. Conversions needed? V. Intermediates needed? VI. Solve

VII. Does the result make sense?

I. StrategyII. Given and unknown

III. Formula

No.No.

Yes.

Learning Objectives• Understand the electromagnetic spectrum• Understand the relationships between and

perform calculations involving wavelength, frequency, and the speed of light

Electromagnetic Spectrum